Intracranial primary leiomyosarcoma arising in a teratoma of the pineal area.

The case of a 33-year-old man with a primary leiomyosarcoma arising in a mature teratoma in the pineal area is presented. The tumor extended into the posterior part of the third ventricle and caused hydrocephalus. Its smooth muscle derivation was confirmed by immunohistochemistry and electron microscopy. The patient has been followed for more than 2 years after surgery and postoperative radiotherapy. He has full working capacity and there are no signs of tumor recurrence. To our knowledge this is the first presentation of a leiomyosarcoma derived from a teratoma in the pineal area.